DALESSANDRO-THESIS-2019.pdf (430.77 kB)

Proving Quadratic Reciprocity: Explanation, Disagreement, Transparency and Depth

Download (430.77 kB)
thesis
posted on 01.12.2019, 00:00 by William D'Alessandro
Abstract Gauss’s quadratic reciprocity theorem is among the most important results in the history of number theory. It’s also among the most mysterious: since its discovery in the late 18th century, mathematicians have regarded reciprocity as a deeply surprising fact in need of explanation. Intriguingly, though, there’s little agreement on how the theorem is best explained. Two quite different kinds of proof are most often praised as explanatory: an elementary argument that gives the theorem an intuitive geometric interpretation, due to Gauss and Eisenstein, and a sophisticated proof using algebraic number theory, due to Hilbert. Philosophers have yet to look carefully at such explanatory disagreements in mathematics. I do so here. According to the view I defend, there are two important explanatory virtues—depth and transparency—which different proofs (and other potential explanations) possess to different degrees. Although not mutually exclusive in principle, the packages of features associated with the two stand in some tension with one another, so that very deep explanations are rarely transparent, and vice versa. After developing the theory of depth and transparency and applying it to the case of quadratic reciprocity, I draw some morals about the nature of mathematical explanation.

History

Advisor

Takloo-Bighash, Ramin

Chair

Takloo-Bighash, Ramin

Department

Mathematics, Statistics and Computer Science

Degree Grantor

University of Illinois at Chicago

Degree Level

Masters

Degree name

MS, Master of Science

Committee Member

Jones, Nathan Tappenden, James

Submitted date

December 2019

Thesis type

application/pdf

Language

en

Issue date

27/11/2019

Exports